Justification of Red List Category
This species has been uplisted to Near Threatened on the basis that it is suspected that it will undergo a moderately rapid population decline over the next three generations owing to the impacts of diclofenac use in livestock, a drug that has caused drastic declines in other Gyps species and appears to be fatal to this species when ingested. The distribution of this species and existing efforts to reduce diclofenac use may limit the impacts.
This species's global population size has apparently not been quantified, although Ferguson-Lees and Christie (2001) suggest that a six-figure population would be realistic. It is therefore preliminarily placed in the band for 100,000-499,999 individuals, assumed to equate to c.66,000-334,000 mature individuals.
It is suspected that this species's population will undergo a decline of 25-29% over the next three generations, owing to the expected impacts of diclofenac use in livestock. A survey in Khodpe, Nepal found that 76% of respondents were aware that vulture populations were decreasing in their area (Joshi et al. 2016).
This species is distributed from western China, Kazakhstan, Uzbekistan, Kyrgyzstan, Tajikistan, Afghanistan and Pakistan, east through the Himalayan mountain range in India, Nepal and Bhutan, to central China and Mongolia. The species is regarded as common in the Qinghai-Tibetan Plateau, China, with wintering populations also found in Yunnan province (Lu et al. 2009, Yang Liu in litt. 2011). It is described as fairly common in parts of Himachal Pradesh, India (especially in Sainj Valley) (V. Jolli in litt. 2014). This species is probably a regular winter visitor in low numbers to the plains of Rajasthan, and in 2013 there were a number of records of vagrants in southern India (Praveen J. in litt. 2012, 2014). It is regarded as a widespread altitudinal migrant in Nepal (C. Inskipp and H. S. Baral in litt. 2011, M. Virani in litt. 2014). It appears to be relatively common in Omnogovi province, especially in Gobi Gurvansaikhan National Park, Mongolia, and some adjacent massifs (D. L. Yong in litt. 2013).
The species has become an almost annual, but rare, winter visitor to Thailand and the Thai-Malay Peninsula (D. L. Yong in litt. 2011, C. Kasorndorkbua in litt. 2012), and has reached the Riau islands. Since 2006 some 10-30 birds are recorded annually passing through northern Thailand (C. Kasorndorkbua in litt. 2016). It also regularly occurs in Kachin state, and probably also Shan and Chin states, Myanmar (D. L. Yong in litt. 2011, J. C. Eames in litt. 2012), but is probably only a vagrant or rare winter visitor to Cambodia (J. C. Eames in litt. 2012). Most birds recorded in Thailand have been in their first year (C. Kasorndorkbua in litt. 2012). It is a scarce and local, but increasing, winter visitor to Bangladesh, where all birds recorded have been immatures (P. Thompson in litt. 2014).
The species's population appears to be stable in Dehradun District, Uttarakhand, India (A. P. Singh in litt. 2014), and elsewhere in India and Nepal (M. Virani in litt. 2014), but appears to have fluctuated in the Upper Mustang region of Nepal, where a decline in 2002-2005 was followed by a partial recovery, probably resulting from immigration from Central Asia (Acharya et al. 2009, K. Paudel and T. Galligan in litt. 2014).
This species inhabits mountainous areas, mostly at 1,200-5,500 m (X. Lu in litt. 2016), but has been recorded up to 6,000 m (Ferguson-Lees and Christie 2001). In winter it moves lower down, with juveniles wandering into the plains. It feeds on carrion (del Hoyo et al. 1994) and regularly visits carcass dumps in South and South-East Asia (Praveen J. in litt. 2012, T. H. Galligan in litt. 2016, D. L. Yong in litt. 2016).
The most serious potential threat to this species is thought to be mortality caused through ingestion of diclofenac and other vulture-toxic non-steroidal anti-inflammatory drugs (NSAIDs) widely used in livestock, particularly in South Asia. Diclofenac has caused drastic declines in three other Gyps species in South Asia since the early 1990s, owing to kidney failure following ingestion, with clinical signs of extensive visceral gout and renal failure, and the drug also appears to be fatal in G. himalayensis (Das et al. 2010). The decline noted in the Upper Mustang region of Nepal in 2002-2005 was thought highly likely to be caused by diclofenac poisoning (Acharya et al. 2009). Since diclofenac was banned in Nepal in 2006, this species has seen partial recovery, at least in part of its range in Nepal, (Paudel et al. 2015) and declines in other Gyps species may have slowed and even reversed (Prakash et al. 2012). However, a wide range of NSAIDs, including one containing diclofenac, were found to be still available for purchase in Mustang District as of February 2012 (R. Acharya per C. Inskipp in litt. 2013). Elsewhere in South Asia, diclofenac use has also decreased, but it remains widely used, thus immature birds dispersing to northern India and Pakistan in winter are still at risk (C. Inskipp and H. S. Baral in litt. 2013, K. Paudel and T. Galligan in litt. 2014). Other potential threats include habitat degradation and a shortage of suitable nesting sites (H. Kala in litt. 2013), as well as the ingestion of herbicides, insecticides and fungicides (Acharya et al. 2009). On the Qinghai-Tibet plateau the main threats appear to be chemical control for pika (Ochotona spp.) and the removal of livestock carcasses (X. Lu in litt. 2016). In Thailand lack of natural food sources has been the sole reason for birds (20 juveniles) being admitted to the Kasetsart University Raptor Rehabilitation Unit (C. Kasorndorkbua in litt. 2012).
Conservation Actions Underway
In Nepal the species is considered Vulnerable (Inskipp et al. 2016). The species will be covered by a Multi-species Action Plan to conserve African Eurasian Vultures which is in preparation for the CMS Raptors MOU (UNEP/CMS 2016). Conservation actions to save Critically Endangered Gyps vultures in South Asia, namely the reduction of diclofenac availability and use, through legislation, law enforcement, education, designation of Vulture-Safe Feeding Sites, and the promotion of alternative drugs, appears to have benefited Gyps species in South Asia, thus the risk to G. himalayensis is also thought to have been reduced (Prakash et al. 2012, C. Inskipp and H. S. Baral in litt. 2013, C. Bowden in litt. 2014, T. H. Galligan in litt. 2016).
Conservation Actions Proposed
Conduct surveys throughout the species's range to assess the population trend. Investigate the threat posed by diclofenac, as well as the potential threats of habitat degradation and limited nest-site availability. Continue to advocate for the enforcement of diclofenac bans. Continue awareness and education campaigns to reduce diclofenac use.
Text account compilers
Harding, M., Ashpole, J, Butchart, S., Taylor, J., Ekstrom, J., Symes, A.
Yong, D., Inskipp, C., Karmacharya, D., Eames, J.C., Liu, Y., Jolli, V., Kasorndorkbua, C., Singh, A., Jayadevan, P., Baral, H., Sherub, S., Paudel, K., Kala, H., Virani, M., Thapa, V., Bowden, C., Galligan, T., Thompson, P., Lu, X.
BirdLife International (2017) Species factsheet: Gyps himalayensis. Downloaded from http://www.birdlife.org on 16/10/2017. Recommended citation for factsheets for more than one species: BirdLife International (2017) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/10/2017.